Krista Won
December 6, 2012
WRIT 340 Illumin Article - Revised
Dr. Ramsey
Technology at the Tip of Your Finger: Contact Lens beyond Correcting Vision
Search Terms: UV light reacting lens, IOP monitoring lens, stem cells and blindness, augmented
reality, Triggerfish, iOptik
Reference Material:
Innovega “I Can See for Inches and Miles”
http://www.youtube.com/watch?feature=player_embedded&v=x70ZKwlC1Es
Innovega iOptik Camera Demo
http://www.youtube.com/watch?feature=player_embedded&v=khWE-GYccRg
Google Project Glass Demo
http://www.youtube.com/watch?v=9c6W4CCU9M4
About the Author: Krista Won is a fourth year architecture student at USC. When she isn’t in
studio making architecture models, she’s traveling across LA seeking a new favorite
restaurant.
Summary: Engineers are discovering modern applications of the contact lens, extending from
correcting vision and aiming to cure blindness. Contact lens implemented with
intraocular pressure sensors would immensely improve the lives of glaucoma patients. It
would free patients from frequent hospital visits and constant intraocular pressure
monitoring through more uncomfortable procedures. Stem cell colonies from a healthy
eye applied to contact lens repair vision loss, up to the point of a nearly full recovery.
Contact lenses are also the subject of nanotechnology experiments. This nanotechnology
is also necessary for the medical applications mentioned, but engineers are looking
beyond to other uses. Companies such as Innovega begin to explore augmented reality
with contact lens. Overlaying the digital and physical world within a field of vision is an
old idea, but the different functions of such technology are innovative. From controlling
your eye’s natural focusing ability to a full functioning phone are ideas of what could be
integrated into your contact lens. The possibilities of contact lens applications are
amazing and with our world’s quickly evolving technology, the possibilities could be
endless.
Introduction
If you do not own a pair of contact lens, you could still guess its size, assuming that it is
small enough to fit on your eye, but big enough to cover your cornea. If you were to hold a
single contact lens, it would be barely bigger than the tip of your finger. Now imagine that
Contact Lens, November 2012
contact lens accommodating a radio, an LED display, and an antenna and control circuit as well
as the simple ability to tint, acting as replacements for sunglasses. Our world is rapidly making
leaping advancements in technology, constantly challenging the minds of innovators to not only
birth new ideas, but also to construct hybrids of past ideas. Contact lenses with an additional UV
protective property is one these advances. But we are capable of reaching far past just using lens
as sunglasses – from curing blindness to fabricating augmented reality. The implementation of
nanotechnology on an object about 125 million people use on a daily basis worldwide is amazing,
but the actual purpose, performance, and success of the nanotechnology is pure innovation [1].
Contact Lens: Basic Types
If you are not one of the lucky people who possess 20/20 vision, you probably instead
possess a pair of glasses or contact lens. Both are instruments of visual correction the when
worn by the user. They specifically aid to correct myopia (nearsightedness), hyperopia
(farsightedness), astigmatism (distorted vision), and presbyopia (need for bifocals). Depending
on the user’s condition, a specific type of lens can be chosen. First created in the 1960’s, PMMA
contact lenses are rigid (or hard) due to its material polymethyl methacrylate (hence its name),
which does not allow oxygen to permeate to the cornea. Instead, as the user blinks, the lens
shifts, making room for tears with oxygen to contact the cornea. These lenses are quite durable
because of their rigid materiality; but because they are uncomfortable, they are the least worn
contacts today. Gas-permeable lenses (or RGPs) are also rigid lenses made of newer plastics
such as silicone and fluoropolymers. These modern rigid lenses allow oxygen to permeate to the
cornea. Since these lenses are still hard in material, they are somewhat uncomfortable to wear,
but an improvement from PMMA. The most worn lenses are soft contact lens, which are
constructed from plastic that becomes flexible when in contact with water. Soft lenses are the
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Contact Lens, November 2012
most comfortable lens, as they cling and naturally form to surface of your eye due to their
malleability. After the lens selection, a user must select the duration of wear. Contact lenses are
created with different life spans, from disposable day-to-day use, two to four weeks of use or the
long lasting toric lens. Toric lens correct astigmatism, which means they should not be worn to
bed, and are not disposable [1]. I happen to own gas permeable lens (toric lens) to correct my
myopia and astigmatism. Despite the contact lenses somewhat ordinary function, engineers are
recognizing new ideas in lens performance that reach past simply correcting myopia all the way
to curing blindness.
UV Protection
Ultraviolet protection manufactured into sunglasses and glasses is very common and has
been utilized for many years. In Singapore, the Institute for Bioengineering and Nanotechnology
began developing a contact lens that carry the same properties as tinted glasses (also called
photochromic lens). When tested in 2009, the dye in the material of the contact lens responded
to UV light rather quickly, faster than tinted glasses. The quick transformation is crucial (taking
about 10-20 seconds in lens and a couple minutes in glasses) when the light environment
suddenly changes – for example, when driving into a tunnel, the driver will need the lens to
adjust in order to see clearly [2]. Successfully integrating UV protection into contact lenses
could revolutionize sunglass wear in general, especially athletic eye wear. Sweaty sunglasses
and hindered peripheral vision would not be a concern when wearing photochromic lens. UV
protection is just a cosmetic supplement for these vision-correcting lenses, just barely scratching
the surface of what could be further done. Although “sun-lenses” would be practical, most
research concerning contact lens focus on biomedical applications.
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Contact Lens, November 2012
Disease Monitoring
Glaucoma is the second-leading cause of blindness in the world, affecting almost 65
million people. There is currently no full cure for glaucoma, only temporary solutions. It is a
disease that can only be detected in its advanced stages, at which point the individual will have
suffered great loss in vision. Glaucoma results from increased pressure from excess fluid in the
eye, harming the optic nerve, thus causing gradual blindness. Any treatment is targeted to stunt
the further loss of vision. Because glaucoma is known to slowly work over time, patients need to
be carefully monitored. Engineers are now developing a microchip, imbedded into a single
contact lens, which monitors fluid pressure in the eye and communicates with a separate device
to record the information. Normally patients would need to sleep overnight at a hospital to be
woken up every hour to take fluid pressure measurements, but with the use of these lenses, the
patient’s fluid pressure can be monitored anytime and anywhere without the trouble of frequent
hospital visits. Since the detector is directly on the eye, it provides instant and detailed data
about the state of glaucoma on the eye, allowing doctors to better diagnose patients [3].
The Swiss medical micro-technology company SENSIMED, a branch of the Swiss
Federal Institute of Technology, engineered a contact lens that could perform as a monitor for
glaucoma patients in 2011. This method of monitoring is possible because human tears coating
the eye contain the same biological cells and data as human blood. The Triggerfish® (see Fig.2)
consists of an imbedded sensor in the lens and comes with an antenna (worn on the forehead)
that transmits the data to the portable recorder (see Fig.3). It constantly checks the intraocular
pressure (IOP) of the patient for up to a whole day. Due to its hand-free and portable nature, the
user is able to go about with daily activities [4]. By using contact lens as medical resources,
doctors and engineers can expand from just glaucoma monitoring to blood-sugar levels for
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Contact Lens, November 2012
diabetics, cholesterol levels, etc. The possibilities for this nanotechnology are amazing and
would greatly assist in patient monitoring and examinations.
Fig.1 SENSIMED Triggerfish® [4] Fig.2 SENSIMED Triggerfish® Device Communication [4]
Curing Blindness
The cure to blindness is something extraordinary, and we may be approaching the cusp of
its discovery. So far, contact lens have been used in medical research for glaucoma, as explained
previously, and now scientists are taking a step further by addressing the end result of glaucoma
– blindness. Nick Di Girolama of the School of Medical Sciences in New South Wales is
leading the research of implanting epithelial stem cells (ESC) into contact lens as the solution.
Blindness stemming from a damaged cornea can be treated by ESC [6]. In his research,
Girolama extracted stem cells from the cornea of a healthy eye and infused them into a special
lens. According to his studies, the healthy stem cells should recolonize in the blind eye,
repairing the damaged cornea with the same biological data from the healthy eye. Three subjects,
who were blind in one eye, were tested with this method and within 10-14 days, Girolama’s
hypotheses were proven correct: two subjects, once legally blind, were now able to read part of
the eye chart and the third subject recovered enough to pass a driving test [6]. This method is in
its early stages of development, but show potential for increased medical application. Contact
lens and their properties have much to offer to the medical world, but that is only the tip of the
iceberg when looking at other aspects in life.
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Contact Lens, November 2012
Augmented Reality
Augmented reality is commonly represented in films such as the Terminator, Iron Man,
as well as any other super spy or robot film with hi-tech glasses or contacts. Live data scrolling
in front of our eyes, a system with facial recognition, video conferencing, and voice activation –
these are all components in augmented vision that could quite possibly evolve into reality. The
concept and development of augmented reality has existed for quite a while now, but the
implementation into our fast advanced technological systems has recently opened up new doors
to explore the overlap between the digital and physical world. The devices that project
augmented reality range from head mounted, eye glasses, virtual retinal display, handheld and
spatial, but our focus is on the contact lens.
Babak Parviz, an electrical engineering professor at the University of Washington, is
producing a prototype of a contact lens consisting of a 450 nanometer wide radio (also called
bionic lens). Ultimately his goal is to develop a full, multi-functional contact lens (see Fig.4).
His research focuses on micro systems integrated into biomedical devices, starting out with
glucose level detector contact lens and continued to LED displays on lens. Currently, he has
successfully implemented a single pixel LED display onto the lens, which blinks a red or blue
light [7].
Fig.3 Parviz’s Contact Lens Design [9]
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Contact Lens, November 2012
Obviously, Parviz’s contact lens has not quite breached the full properties of augmented
reality, but it is the ultimate goal that pushes his design to carefully explore and experiment each
element that contributes to it. Although a radio-supporting lens is his first step towards
augmented reality, it proves to be ambitious; as seen in Figure 4, the lens must hold mechanics
such as an energy-storage module, control circuit, telecommunication antenna, display circuit,
radio and power conversion circuit, etc. The success of radio implementation is crucial before
attempting any other elements of augmented reality because it is the chief system of
communication between the lens and other devices.
Innovega is a company producing the iOptik™, their own version of augmented reality.
Their research in augmented reality and lens are further advanced than that of Parviz’s, but their
objective and audience are different as well. They focus on enhancing human vision by allowing
the human eye to focus on an object very close by or very far away – much like how a camera
lens or binoculars perform. While you are focused on an object in the foreground, everything in
the background would normally be fuzzy, but while wearing the iOptik™ lens, you can
simultaneously focus on both fore and background without any fuzziness. Such an experience is
achieved by the delicate engineering of the contact lens. Innovega created an outer and center
filter with a display lens (see Fig.5 and 6). Stephen Willey, the CEO of Innovega, explains the
physics behind the lens:
Display light passes through the small central optic which, in combination with the eye’s normal
optics, focuses the display light onto the retina. The display light that falls on the outer portion of
the contact lens is blocked by the outer filter to prevent it from interfering with the view of the
display. Ambient light from the environment is able to pass through the outer filter. This light
enters the pupil and is focused onto the retina. Almost half of all consumers benefit from a lens
prescription so this is incorporated into the lens. Light from the environment that passes through
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Contact Lens, November 2012
the center focusing optic is first defocused and is then blocked by the center filter preventing this
defocused light from interfering with the wearer’s normal view of the surroundings [10].
Innovega’s design of the iOptik™ lens allows the user to focus on the small display on which the
digital world will be projected onto. Because the user can optically focus on very close images,
it eliminates any use of eyewear or devices attached to our bodies in order to read the display,
while still being able to see the world around us with no difference in vision. It deals with near
and far-sightedness, or macro and micro vision (not to be confused with microscopic or
binocular vision). Just like when taking a picture of a close object, let’s say, a flower, the camera
lens will focus on the flower, automatically blurring the objects in the background, just as our
eyes naturally do. The construction of the iOptik™ lens masks the “blurring” effect, allowing us
to focus on anything in our field of vision without actually having to shift focus – the lens does
that for us.
Fig.4 iOptik™ Lens [11]
Fig.5 iOptik™ Lens Performance Diagram [11]
This particular design can also be incorporated into battlefield and combat situations –
training or reality. It is hands-free, lightweight and easy to use – crucial components for a
soldier on duty when using advanced technology (unlike previously attempted bulky headgear).
If this tiny piece of technology was added to the military, it would greatly advance the
presentation of technical data, satellite information, communication, live camera feeds and maps
[11]. On a day-to-day basis, elements similar to a smartphone would be accessed, such as phone
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Contact Lens, November 2012
calls and messages, camera, map, weather data, calendar and possibly basic internet connection.
Everyday tasks like a phone call to a friend just by voice activation and without pulling out your
mobile device would become simplified and quicker.
Conclusion
As our world progresses further into the technology-dominant age, our lives are
continually molded by the world around us. If something as small as contact lens could be
imbedded with nanotechnology and data, imagine our world a step further. Engineers
continually identify new operations for contact lens, ranging from practical, cosmetic, medical,
entertainment and combat, in order to simply improve our lives to the more complex improving
of nanotechnology.
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Contact Lens, November 2012
Bibliography
[1] University of Michigan Kellog Eye Center. Contact Lenses [Online]. Available:
http://www.kellogg.umich.edu/patientcare/conditions/contact.lenses.html
[2] J. Chu. (2009, November 10). Contact Lenses that Respond to Light [Online]. Available:
http://www.technologyreview.com/news/416213/contact-lenses-that-respond-to-light/
[3] P. Patel. (2010, June). Diagnostic Contacts [Online]. Available:
http://spectrum.ieee.org/biomedical/diagnostics/diagnostic-contacts/1
[4] SENSIMED Triggerfish® - Continuous IOP Monitoring [Online]. Available:
http://www.sensimed.ch/en/products/sensimed-triggerfishr.html
[5] “Efficacy of 24-hour Intraocular Pressure Fluctuation Recording With the SENSIMED
Triggerfish Contact Lens Sensor,” Sensimed AG. Geneva, Switzerland.
Available: http://clinicaltrials.gov/ct2/show/NCT01390779
[6] N. Di Girolamo, “Stem cells of the human cornea,” Oxford Journals: British Medical
Bulletin. June 16, 2011 [Online]. Available:
http://bmb.oxfordjournals.org/contest/early/2011/06/15/bmb.ldr026.full.pdf
[7] B. Parviz. (2009, September). Augmented Reality in a Contact Lens [Online]. Available:
http://spectrum.ieee.org/biomedical/bionics/augmented-reality-in-a-contact-lens/0
[8] B. Parviz. (2011, February). Building Microsystems on the Eye [Online]. Available:
http://www.wesolveforx.com/#t=t&n=0ec8b0c2
[9] E. Cooper. (2009, September). A Twinkle in the Eye [Online]. Available:
http://spectrum.ieee.org/biomedical/bionics/augmented-reality-in-a-contact-lens/eyesb1
[10] R. Sprague. Benefits [Online]. Available: http://innovega-inc.com/benefits.php
[11] R. Sprague. A New Architecture [Online]. Available: http://innovega-inc.com/newarchitecture.php
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